It's hard to overestimate the importance of the Rolling Stones in rock and roll history. The group, which formed in London in 1962, distilled so much of the music that had come before it and has exerted a decisive influence on so much that has come after. Every album the group released through the early Seventies - from The Rolling Stones in 1964 to Exile on Main Street in 1972 - is essential not simply to an understanding of the music of that era, but to an understanding of the era itself.

Though the Stones were not overtly political in their early years, their obsession with African American music - from Robert Johnson, Muddy Waters and Howlin' Wolf to Chuck Berry, Marvin Gaye and Don Covay - struck a chord that resonated with the goals of the civil rights movement. Soon, of course, the Stones - singer Mick Jagger, guitarists Keith Richards and Brian Jones, bassist Bill Wyman and drummer Charlie Watts, in those days - became synonymous with the rebellious attitude of that era. Songs like (I Can't Get No) Satisfaction, Street Fighting Man, Sympathy for the Devil and Gimme Shelter captured the violence, frustration and chaos of that era.

For the Stones, the Sixties were not a time of peace and love. More significantly, though, the Stones have set a standard for live performance during this time. When the Stones began to be introduced on their 1969 tour as The Greatest Rock and Roll Band in the World, they were staking that claim on the basis of their live performances. It was almost fashionable for bands to withdraw from the road at that time - Bob Dylan and the Beatles had both done so. But the Stones set out to prove that writing brilliant songs and making powerful records did not mean that you were too lofty to get up in front of your fans and rock them until their bones rattled.

The Stones' live shows - epitomised, of course, by Jagger's galvanising erotic choreography - had earned the band its reputation in its earliest years, and that flame was being rekindled. Musicians live and create in the moment, and that's why fans still go see the Stones. Certainly there's also a catalogue of songs that only a handful of artists could rival. Surely there's also the desire to encounter a band that has played a pristine role in defining our very idea of what rock & roll is. But seeing the Rolling Stones live is to see a working band playing as hard as they can, and there's no last time for that.